Add-on module for a homogeneous unit telephone set



FIG. 1 is a front, top and right side perspective view of an add-on module for a homogeneous unit telephone set showing our new design;

FIG. 2 is a bottom plan view;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a front elevational view thereof; and

FIGS. 6 and 7 are respectively left and right side elevational views thereof. 

The ornamental design for an add-on module for a homogeneous unit telephone set, as shown and described. 